A method for processing an az31b magnesium alloy sheet

Abstract

The application is particularly a processing method of AZ31B magnesium alloy plate, which solves the problem of insufficient preparation technology of the existing magnesium alloy plate due to its own reasons. The processing method of the AZ31B magnesium alloy plate is realized by the following steps: step S1: homogenizing treatment is performed on the AZ31B magnesium alloy ingot; step S2: the AZ31B magnesium alloy ingot is placed into an extrusion die for first extrusion; step S3: the AZ31B magnesium alloy ingot is placed into the extrusion die for second large deformation extrusion; and step S4: the AZ31B magnesium alloy ingot is placed into a rolling roller for rolling. The method has simple process flow and is easy to operate. The equipment used for processing the AZ31B magnesium alloy plate is common equipment, and the industrialized production of the AZ31B magnesium alloy plate with low cost and high performance is realized. Meanwhile, the AZ31B magnesium alloy plate with a thickness of 1.5 mm to 2.5 mm can be processed by the method, and the tensile strength is greater than or equal to 310 Mpa, and the elongation rate is greater than or equal to 25%. The method has the advantages of low cost, high material utilization rate, stable plate performance, and large market demand.

Description

Technical Field

[0001] This invention relates to the field of magnesium alloy sheet processing technology, specifically a processing method for AZ31B magnesium alloy sheet. Background Technology

[0002] Magnesium alloys are widely used in the automotive, computer, communications, and aerospace industries due to their low density, high specific strength, and excellent damping properties. However, magnesium's close-packed hexagonal crystal structure and limited number of open slip systems make deformation difficult at room temperature. Furthermore, misconceptions about the flammability and corrosion resistance of magnesium alloys have hindered the large-scale application of wrought magnesium alloy sheets, and research on wrought magnesium alloys and forming processes remains insufficient. Wrought magnesium alloy sheets, profiles, and forgings have not yet been widely adopted in the civilian sector. Given the societal demands for resource conservation and pollution reduction, and considering the strategic requirements for sustainable development, wrought magnesium alloys urgently require a shift in perspective, accelerated research, and promotion of their application in the civilian sector.

[0003] Wrought magnesium alloys are mainly produced through plastic processing methods such as forging, stamping, extrusion, rolling, and drawing. Among these, rolling is the most widely used due to its high production efficiency, large output, and variety of products. However, because magnesium alloys have poor plastic deformation capabilities and tend to exhibit severe anisotropy in rolled sheets, the progress of magnesium alloy sheet rolling technology has been relatively slow, hindering the development of magnesium alloy sheet manufacturing technology.

[0004] Therefore, it is necessary to invent a processing method for AZ31B magnesium alloy sheets to obtain low-cost, high-performance AZ31B magnesium alloy sheets and realize the industrial production of magnesium alloys. Summary of the Invention

[0005] In order to solve the problem of insufficient preparation technology of existing magnesium alloy plates due to their own limitations, the present invention provides a processing method for AZ31B magnesium alloy plates.

[0006] This invention is achieved using the following technical solution:

[0007] A processing method for AZ31B magnesium alloy sheet, comprising the following steps:

[0008] Step S1: First, the AZ31B magnesium alloy ingot is machined and polished; then, the AZ31B magnesium alloy ingot is wrapped with dry MgO powder and placed in a heating furnace for homogenization treatment at a temperature of 400℃~430℃ for 10h~15h; after the homogenization treatment, the AZ31B magnesium alloy ingot is cooled with the heating furnace; after cooling, the AZ31B magnesium alloy ingot is taken out and polished again.

[0009] Step S2: Place the AZ31B magnesium alloy ingot obtained in step S1 into a heating furnace and heat it to 320℃~400℃ and hold it for 30 minutes. At the same time, heat the extrusion die to 320℃~400℃. Then, take out the AZ31B magnesium alloy ingot and place it into the extrusion die for the first extrusion. The extrusion angle is 90°, the extrusion speed is 0.2m / s~0.4m / s, and the extrusion ratio is 4:1. After the extrusion is completed, take out the AZ31B magnesium alloy ingot and immediately water quench it.

[0010] Step S3: Place the AZ31B magnesium alloy ingot obtained in step S2 into a heating furnace and heat it to 250℃~350℃ and hold it for 30 minutes. At the same time, heat the extrusion die to 250℃~350℃. Then, take out the AZ31B magnesium alloy ingot and place it into the extrusion die for a second large deformation extrusion. The extrusion angle is 30°, the extrusion speed is 0.2m / s~0.4m / s, and the extrusion ratio is 25:1. After the extrusion is completed, take out the AZ31B magnesium alloy ingot and let it cool naturally.

[0011] Step S4: Place the AZ31B magnesium alloy ingot obtained in step S3 into a heating furnace and heat it to 300℃~400℃ and hold it for 30 minutes. At the same time, heat the rolls to 200℃~300℃. Then, take out the AZ31B magnesium alloy ingot and place it into the rolls for rolling. After each rolling pass, place the AZ31B magnesium alloy ingot into a heating furnace and heat it to 400℃ and hold it for 5 minutes. Then, perform the next rolling pass. The rolling speed of each rolling pass is 0.5m / s~1m / s, the reduction of each rolling pass is 5%~10%, and the rolling direction of each rolling pass is consistent. Repeat the rolling operation until the AZ31B magnesium alloy ingot is rolled into an AZ31B magnesium alloy plate with a thickness of 1.5mm~2.5mm.

[0012] This method has a simple process and is easy to operate. The equipment used to process AZ31B magnesium alloy sheets is all common equipment, realizing the industrial production of low-cost, high-performance AZ31B magnesium alloy sheets. At the same time, this method can process AZ31B magnesium alloy sheets with a thickness of 1.5mm to 2.5mm, with a tensile strength ≥310Mpa and an elongation ≥25%. Furthermore, it has the advantages of low cost, high material utilization, and stable sheet performance, and has a large market demand. Attached Figure Description

[0013] Figure 1 This is a process flow diagram of the present invention.

[0014] Figure 2 This is a metallographic image of the as-cast microstructure of the AZ31B magnesium alloy in this invention at 200 μm.

[0015] Figure 3 This is a metallographic image of the as-cast microstructure of the AZ31B magnesium alloy in this invention at 100 μm.

[0016] Figure 4 This is a metallographic image of the microstructure of AZ31B magnesium alloy at 200 μm after homogenization treatment in step S1.

[0017] Figure 5 This is a metallographic image of the microstructure of AZ31B magnesium alloy at 100 μm after homogenization treatment in step S1.

[0018] Figure 6 This is a metallographic image of the microstructure of AZ31B magnesium alloy after extrusion at 200 μm in step S3.

[0019] Figure 7 This is a metallographic image of the microstructure of AZ31B magnesium alloy after extrusion at 100 μm in step S3.

[0020] Figure 8 This is a metallographic image of the microstructure of AZ31B magnesium alloy after rolling deformation in step S4 at 200 μm.

[0021] Figure 9 This is a metallographic image of the microstructure of AZ31B magnesium alloy at 100 μm after rolling deformation in step S4.

[0022] In the diagram: 1-AZ31B magnesium alloy ingot, 2-heating furnace, 3-extrusion die, 4-roll, 5-AZ31B magnesium alloy sheet. Detailed Implementation

[0023] This invention achieves microstructure control of AZ31B magnesium alloy by utilizing a homogenization process to control the Mg second-phase particles in the alloy grains. 17 Al 12 The distribution of elements and the quantity and distribution of twins ensure a uniform distribution of elements in the AZ31B magnesium alloy without causing excessive grain growth, facilitating subsequent large deformation processes and performance improvement. Simultaneously, homogenization treatment eliminates component segregation, ensures a uniform microstructure, and improves the formability of the AZ31B magnesium alloy ingot. A well-developed homogenization process can maximize the development of the ultimate properties of AZ31B magnesium alloy sheets, achieving the expected low-cost, high-performance, and realizing the industrial-scale production of AZ31B magnesium alloy. Its metallographic structure is shown in the attached figure. Figure 4 Appendix Figure 5 .

[0024] This invention, through two extrusion deformations and hot rolling, enables the matrix microstructure to possess a fully dynamic recrystallized microstructure composed of equiaxed recrystallized grains under a continuous and discontinuous dynamic recrystallization mechanism. Its metallographic structure is shown in the attached figure. Figure 6 -Appendix Figure 9Meanwhile, dynamic recrystallization greatly reduces the average grain size of the matrix, significantly improving the mechanical properties of AZ31B magnesium alloy.

[0025] The deformation of AZ31B magnesium alloy mainly takes two forms: twinning and slip. Within the deformation temperature range of 250℃ to 450℃, dynamic recrystallization occurs during deformation of AZ31B magnesium alloy. When the deformation temperature is below 300℃, twinning plays a certain role in plastic deformation. As the temperature increases, the proportion of slip increases, providing nucleation conditions for dynamic recrystallization. During medium-low temperature rolling of magnesium alloy, i.e., rolling temperature of 250℃ to 350℃, twinning induces recrystallization, forming localized "necklace"-shaped recrystallized grains. As the rolling temperature increases, the proportion of twins in the matrix decreases, and the "necklace"-shaped recrystallization morphology decreases or disappears. With increasing rolling temperature, the matrix structure becomes more uniform during high-temperature rolling, but when the rolling temperature is above 400℃, the deformed grains become significantly larger. Therefore, the optimal deformation temperature for magnesium alloy is in the range of 300℃ to 400℃, exhibiting low deformation resistance, good plasticity, and ease of forming.

[0026] Example 1

[0027] A processing method for AZ31B magnesium alloy sheet, as shown in the attached figure. Figure 1 As shown, this method is implemented using the following steps:

[0028] Step S1: First, the AZ31B magnesium alloy ingot 1 is machined and polished; then, the AZ31B magnesium alloy ingot 1 is wrapped with dry MgO powder and placed in the heating furnace 2 for homogenization treatment at a temperature of 400℃ for 12 hours; after the homogenization treatment is completed, the AZ31B magnesium alloy ingot 1 is cooled with the heating furnace 2; after cooling, the AZ31B magnesium alloy ingot 1 is taken out and polished again.

[0029] Step S2: Place the AZ31B magnesium alloy ingot 1 obtained in step S1 into the heating furnace 2 and heat it to 400℃ and hold it for 30 minutes. At the same time, heat the extrusion die 3 to 400℃. Then, take out the AZ31B magnesium alloy ingot 1 and put it into the extrusion die 3 for the first extrusion. The extrusion angle is 90°, the extrusion speed is 0.2m / s, and the extrusion ratio is 4:1. After the extrusion is completed, take out the AZ31B magnesium alloy ingot 1 and immediately water quench it.

[0030] Step S3: Place the AZ31B magnesium alloy ingot 1 obtained in step S2 into the heating furnace 2 and heat it to 250°C and hold it for 30 minutes. At the same time, heat the extrusion die 3 to 250°C. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the extrusion die 3 for a second large deformation extrusion. The extrusion angle is 30°, the extrusion speed is 0.2 m / s, and the extrusion ratio is 25:1. After the extrusion is completed, take out the AZ31B magnesium alloy ingot 1 and let it cool naturally.

[0031] Step S4: Place the AZ31B magnesium alloy ingot 1 obtained in step S3 into the heating furnace 2 and heat it to 300°C and hold it for 30 minutes. At the same time, heat the rolls 4 to 200°C. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the rolls 4 for rolling. After each rolling pass, place the AZ31B magnesium alloy ingot 1 into the heating furnace 2 and heat it to 400°C and hold it for 5 minutes. Then, perform the next rolling pass. The rolling speed of each rolling pass is 1 m / s, the reduction of each rolling pass is 5% to 10%, and the rolling direction of each rolling pass is consistent. Repeat the rolling operation until the AZ31B magnesium alloy ingot 1 is rolled into an AZ31B magnesium alloy plate 5 with a thickness of 2 mm.

[0032] The heating furnace 2 is an electric resistance furnace; the diameter of the roller 4 is 180mm.

[0033] Example 2

[0034] A processing method for AZ31B magnesium alloy sheet, as shown in the attached figure. Figure 1 As shown, this method is implemented using the following steps:

[0035] Step S1: First, the AZ31B magnesium alloy ingot 1 is machined and polished; then, the AZ31B magnesium alloy ingot 1 is wrapped with dry MgO powder and placed in the heating furnace 2 for homogenization treatment at a temperature of 410℃ for 12 hours; after the homogenization treatment is completed, the AZ31B magnesium alloy ingot 1 is cooled with the heating furnace 2; after cooling, the AZ31B magnesium alloy ingot 1 is taken out and polished again.

[0036] Step S2: Place the AZ31B magnesium alloy ingot 1 obtained in step S1 into the heating furnace 2 and heat it to 400℃ and hold it for 30 minutes. At the same time, heat the extrusion die 3 to 400℃. Then, take out the AZ31B magnesium alloy ingot 1 and put it into the extrusion die 3 for the first extrusion. The extrusion angle is 90°, the extrusion speed is 0.2m / s, and the extrusion ratio is 4:1. After the extrusion is completed, take out the AZ31B magnesium alloy ingot 1 and immediately water quench it.

[0037] Step S3: Place the AZ31B magnesium alloy ingot 1 obtained in step S2 into the heating furnace 2 and heat it to 350°C and hold it for 30 minutes. At the same time, heat the extrusion die 3 to 350°C. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the extrusion die 3 for a second large deformation extrusion. The extrusion angle is 30°, the extrusion speed is 0.2 m / s, and the extrusion ratio is 25:1. After the extrusion is completed, take out the AZ31B magnesium alloy ingot 1 and let it cool naturally.

[0038] Step S4: Place the AZ31B magnesium alloy ingot 1 obtained in step S3 into the heating furnace 2 and heat it to 350°C and hold it for 30 minutes. At the same time, heat the rolls 4 to 200°C. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the rolls 4 for rolling. After each rolling pass, place the AZ31B magnesium alloy ingot 1 into the heating furnace 2 and heat it to 400°C and hold it for 5 minutes. Then, perform the next rolling pass. The rolling speed of each rolling pass is 1 m / s, the reduction of each rolling pass is 5% to 10%, and the rolling direction of each rolling pass is consistent. Repeat the rolling operation until the AZ31B magnesium alloy ingot 1 is rolled into an AZ31B magnesium alloy plate 5 with a thickness of 2 mm.

[0039] The heating furnace 2 is an electric resistance furnace; the diameter of the roller 4 is 180mm.

[0040] Example 3

[0041] A processing method for AZ31B magnesium alloy sheet, as shown in the attached figure. Figure 1 As shown, this method is implemented using the following steps:

[0042] Step S1: First, the AZ31B magnesium alloy ingot 1 is machined and polished; then, the AZ31B magnesium alloy ingot 1 is wrapped with dry MgO powder and placed in the heating furnace 2 for homogenization treatment at a temperature of 420℃ for 15 hours; after the homogenization treatment is completed, the AZ31B magnesium alloy ingot 1 is cooled with the heating furnace 2; after cooling, the AZ31B magnesium alloy ingot 1 is taken out and polished again.

[0043] Step S2: Place the AZ31B magnesium alloy ingot 1 obtained in step S1 into the heating furnace 2 and heat it to 350°C and hold it for 30 minutes. At the same time, heat the extrusion die 3 to 350°C. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the extrusion die 3 for the first extrusion. The extrusion angle is 90°, the extrusion speed is 0.2m / s, and the extrusion ratio is 4:1. After the extrusion is completed, take out the AZ31B magnesium alloy ingot 1 and immediately water quench it.

[0044] Step S3: Place the AZ31B magnesium alloy ingot 1 obtained in step S2 into the heating furnace 2 and heat it to 350°C and hold it for 30 minutes. At the same time, heat the extrusion die 3 to 350°C. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the extrusion die 3 for a second large deformation extrusion. The extrusion angle is 30°, the extrusion speed is 0.2 m / s, and the extrusion ratio is 25:1. After the extrusion is completed, take out the AZ31B magnesium alloy ingot 1 and let it cool naturally.

[0045] Step S4: Place the AZ31B magnesium alloy ingot 1 obtained in step S3 into the heating furnace 2 and heat it to 400℃ and hold it for 30 minutes. At the same time, heat the rolls 4 to 200℃. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the rolls 4 for rolling. After each rolling pass, place the AZ31B magnesium alloy ingot 1 into the heating furnace 2 and heat it to 400℃ and hold it for 5 minutes. Then, perform the next rolling pass. The rolling speed of each rolling pass is 1 m / s, the reduction of each rolling pass is 5% to 10%, and the rolling direction of each rolling pass is consistent. Repeat the rolling operation until the AZ31B magnesium alloy ingot 1 is rolled into an AZ31B magnesium alloy plate 5 with a thickness of 2 mm.

[0046] The heating furnace 2 is an electric resistance furnace; the diameter of the roller 4 is 180mm.

[0047] Example 4

[0048] A processing method for AZ31B magnesium alloy sheet, as shown in the attached figure. Figure 1 As shown, this method is implemented using the following steps:

[0049] Step S1: First, the AZ31B magnesium alloy ingot 1 is machined and polished; then, the AZ31B magnesium alloy ingot 1 is wrapped with dry MgO powder and placed in the heating furnace 2 for homogenization treatment at a temperature of 430℃ for 12 hours; after the homogenization treatment, the AZ31B magnesium alloy ingot 1 is cooled with the heating furnace 2; after cooling, the AZ31B magnesium alloy ingot 1 is taken out and polished again.

[0050] Step S2: Place the AZ31B magnesium alloy ingot 1 obtained in step S1 into the heating furnace 2 and heat it to 350°C and hold it for 30 minutes. At the same time, heat the extrusion die 3 to 350°C. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the extrusion die 3 for the first extrusion. The extrusion angle is 90°, the extrusion speed is 0.2m / s, and the extrusion ratio is 4:1. After the extrusion is completed, take out the AZ31B magnesium alloy ingot 1 and immediately water quench it.

[0051] Step S3: Place the AZ31B magnesium alloy ingot 1 obtained in step S2 into the heating furnace 2 and heat it to 300°C and hold it for 30 minutes. At the same time, heat the extrusion die 3 to 300°C. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the extrusion die 3 for a second large deformation extrusion. The extrusion angle is 30°, the extrusion speed is 0.2m / s, and the extrusion ratio is 25:1. After the extrusion is completed, take out the AZ31B magnesium alloy ingot 1 and let it cool naturally.

[0052] Step S4: Place the AZ31B magnesium alloy ingot 1 obtained in step S3 into the heating furnace 2 and heat it to 350°C and hold it for 30 minutes. At the same time, heat the rolls 4 to 200°C. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the rolls 4 for rolling. After each rolling pass, place the AZ31B magnesium alloy ingot 1 into the heating furnace 2 and heat it to 400°C and hold it for 5 minutes. Then, perform the next rolling pass. The rolling speed of each rolling pass is 1 m / s, the reduction of each rolling pass is 5% to 10%, and the rolling direction of each rolling pass is consistent. Repeat the rolling operation until the AZ31B magnesium alloy ingot 1 is rolled into an AZ31B magnesium alloy plate 5 with a thickness of 2 mm.

[0053] The heating furnace 2 is an electric resistance furnace; the diameter of the roller 4 is 180mm.

[0054] Example 5

[0055] A processing method for AZ31B magnesium alloy sheet, as shown in the attached figure. Figure 1 As shown, this method is implemented using the following steps:

[0056] Step S1: First, the AZ31B magnesium alloy ingot 1 is machined and polished; then, the AZ31B magnesium alloy ingot 1 is wrapped with dry MgO powder and placed in the heating furnace 2 for homogenization treatment at a temperature of 420℃ for 12 hours; after the homogenization treatment is completed, the AZ31B magnesium alloy ingot 1 is cooled with the heating furnace 2; after cooling, the AZ31B magnesium alloy ingot 1 is taken out and polished again.

[0057] Step S2: Place the AZ31B magnesium alloy ingot 1 obtained in step S1 into the heating furnace 2 and heat it to 400℃ and hold it for 30 minutes. At the same time, heat the extrusion die 3 to 400℃. Then, take out the AZ31B magnesium alloy ingot 1 and put it into the extrusion die 3 for the first extrusion. The extrusion angle is 90°, the extrusion speed is 0.2m / s, and the extrusion ratio is 4:1. After the extrusion is completed, take out the AZ31B magnesium alloy ingot 1 and immediately water quench it.

[0058] Step S3: Place the AZ31B magnesium alloy ingot 1 obtained in step S2 into the heating furnace 2 and heat it to 300°C and hold it for 30 minutes. At the same time, heat the extrusion die 3 to 300°C. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the extrusion die 3 for a second large deformation extrusion. The extrusion angle is 30°, the extrusion speed is 0.2m / s, and the extrusion ratio is 25:1. After the extrusion is completed, take out the AZ31B magnesium alloy ingot 1 and let it cool naturally.

[0059] Step S4: Place the AZ31B magnesium alloy ingot 1 obtained in step S3 into the heating furnace 2 and heat it to 400℃ and hold it for 30 minutes. At the same time, heat the rolls 4 to 200℃. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the rolls 4 for rolling. After each rolling pass, place the AZ31B magnesium alloy ingot 1 into the heating furnace 2 and heat it to 400℃ and hold it for 5 minutes. Then, perform the next rolling pass. The rolling speed of each rolling pass is 1 m / s, the reduction of each rolling pass is 5% to 10%, and the rolling direction of each rolling pass is consistent. Repeat the rolling operation until the AZ31B magnesium alloy ingot 1 is rolled into an AZ31B magnesium alloy plate 5 with a thickness of 2 mm.

[0060] The heating furnace 2 is an electric resistance furnace; the diameter of the roller 4 is 180mm.

[0061] Example 6

[0062] A processing method for AZ31B magnesium alloy sheet, as shown in the attached figure. Figure 1 As shown, this method is implemented using the following steps:

[0063] Step S1: First, the AZ31B magnesium alloy ingot 1 is machined and polished; then, the AZ31B magnesium alloy ingot 1 is wrapped with dry MgO powder and placed in the heating furnace 2 for homogenization treatment at a temperature of 400℃ for 10 hours; after the homogenization treatment is completed, the AZ31B magnesium alloy ingot 1 is cooled with the heating furnace 2; after cooling, the AZ31B magnesium alloy ingot 1 is taken out and polished again.

[0064] Step S2: Place the AZ31B magnesium alloy ingot 1 obtained in step S1 into the heating furnace 2 and heat it to 320°C and hold it for 30 minutes. At the same time, heat the extrusion die 3 to 320°C. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the extrusion die 3 for the first extrusion. The extrusion angle is 90°, the extrusion speed is 0.2 m / s, and the extrusion ratio is 4:1. After the extrusion is completed, take out the AZ31B magnesium alloy ingot 1 and immediately water quench it.

[0065] Step S3: Place the AZ31B magnesium alloy ingot 1 obtained in step S2 into the heating furnace 2 and heat it to 250°C and hold it for 30 minutes. At the same time, heat the extrusion die 3 to 250°C. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the extrusion die 3 for a second large deformation extrusion. The extrusion angle is 30°, the extrusion speed is 0.2 m / s, and the extrusion ratio is 25:1. After the extrusion is completed, take out the AZ31B magnesium alloy ingot 1 and let it cool naturally.

[0066] Step S4: Place the AZ31B magnesium alloy ingot 1 obtained in step S3 into the heating furnace 2 and heat it to 300°C and hold it for 30 minutes. At the same time, heat the rolls 4 to 200°C. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the rolls 4 for rolling. After each rolling pass, place the AZ31B magnesium alloy ingot 1 into the heating furnace 2 and heat it to 400°C and hold it for 5 minutes. Then, perform the next rolling pass. The rolling speed of each rolling pass is 0.5 m / s, the reduction of each rolling pass is 5%, and the rolling direction of each rolling pass is consistent. Repeat the rolling operation until the AZ31B magnesium alloy ingot 1 is rolled into an AZ31B magnesium alloy plate 5 with a thickness of 1.5 mm.

[0067] The heating furnace 2 is an electric resistance furnace; the diameter of the roller 4 is 180mm.

[0068] Example 7

[0069] A processing method for AZ31B magnesium alloy sheet, as shown in the attached figure. Figure 1 As shown, this method is implemented using the following steps:

[0070] Step S1: First, the AZ31B magnesium alloy ingot 1 is machined and polished; then, the AZ31B magnesium alloy ingot 1 is wrapped with dry MgO powder and placed in the heating furnace 2 for homogenization treatment at a temperature of 420℃ for 13 hours; after the homogenization treatment, the AZ31B magnesium alloy ingot 1 is cooled with the heating furnace 2; after cooling, the AZ31B magnesium alloy ingot 1 is taken out and polished again.

[0071] Step S2: Place the AZ31B magnesium alloy ingot 1 obtained in step S1 into the heating furnace 2 and heat it to 360°C and hold it for 30 minutes. At the same time, heat the extrusion die 3 to 360°C. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the extrusion die 3 for the first extrusion. The extrusion angle is 90°, the extrusion speed is 0.3m / s, and the extrusion ratio is 4:1. After the extrusion is completed, take out the AZ31B magnesium alloy ingot 1 and immediately water quench it.

[0072] Step S3: Place the AZ31B magnesium alloy ingot 1 obtained in step S2 into the heating furnace 2 and heat it to 300°C and hold it for 30 minutes. At the same time, heat the extrusion die 3 to 300°C. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the extrusion die 3 for a second large deformation extrusion. The extrusion angle is 30°, the extrusion speed is 0.3 m / s, and the extrusion ratio is 25:1. After the extrusion is completed, take out the AZ31B magnesium alloy ingot 1 and let it cool naturally.

[0073] Step S4: Place the AZ31B magnesium alloy ingot 1 obtained in step S3 into the heating furnace 2 and heat it to 350°C and hold it for 30 minutes. At the same time, heat the rolls 4 to 250°C. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the rolls 4 for rolling. After each rolling pass, place the AZ31B magnesium alloy ingot 1 into the heating furnace 2 and heat it to 400°C and hold it for 5 minutes. Then, perform the next rolling pass. The rolling speed of each rolling pass is 0.8 m / s, the reduction of each rolling pass is 8%, and the rolling direction of each rolling pass is consistent. Repeat the rolling operation until the AZ31B magnesium alloy ingot 1 is rolled into an AZ31B magnesium alloy plate 5 with a thickness of 2 mm.

[0074] The heating furnace 2 is an electric resistance furnace; the diameter of the roller 4 is 180mm.

[0075] Example 8

[0076] A processing method for AZ31B magnesium alloy sheet, as shown in the attached figure. Figure 1 As shown, this method is implemented using the following steps:

[0077] Step S1: First, the AZ31B magnesium alloy ingot 1 is machined and polished; then, the AZ31B magnesium alloy ingot 1 is wrapped with dry MgO powder and placed in the heating furnace 2 for homogenization treatment at a temperature of 430℃ for 15 hours; after the homogenization treatment, the AZ31B magnesium alloy ingot 1 is cooled with the heating furnace 2; after cooling, the AZ31B magnesium alloy ingot 1 is taken out and polished again.

[0078] Step S2: Place the AZ31B magnesium alloy ingot 1 obtained in step S1 into the heating furnace 2 and heat it to 400℃ and hold it for 30 minutes. At the same time, heat the extrusion die 3 to 400℃. Then, take out the AZ31B magnesium alloy ingot 1 and put it into the extrusion die 3 for the first extrusion. The extrusion angle is 90°, the extrusion speed is 0.4m / s, and the extrusion ratio is 4:1. After the extrusion is completed, take out the AZ31B magnesium alloy ingot 1 and immediately water quench it.

[0079] Step S3: Place the AZ31B magnesium alloy ingot 1 obtained in step S2 into the heating furnace 2 and heat it to 350°C and hold it for 30 minutes. At the same time, heat the extrusion die 3 to 350°C. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the extrusion die 3 for a second large deformation extrusion. The extrusion angle is 30°, the extrusion speed is 0.4 m / s, and the extrusion ratio is 25:1. After the extrusion is completed, take out the AZ31B magnesium alloy ingot 1 and let it cool naturally.

[0080] Step S4: Place the AZ31B magnesium alloy ingot 1 obtained in step S3 into the heating furnace 2 and heat it to 400℃ and hold it for 30 minutes. At the same time, heat the roll 4 to 300℃. Then, take out the AZ31B magnesium alloy ingot 1 and place it into the roll 4 for rolling. After each rolling pass, place the AZ31B magnesium alloy ingot 1 into the heating furnace 2 and heat it to 400℃ and hold it for 5 minutes. Then, perform the next rolling pass. The rolling speed of each rolling pass is 1m / s, the reduction of each rolling pass is 10%, and the rolling direction of each rolling pass is consistent. Repeat the rolling operation until the AZ31B magnesium alloy ingot 1 is rolled into an AZ31B magnesium alloy plate 5 with a thickness of 2.5mm.

[0081] The heating furnace 2 is an electric resistance furnace; the diameter of the roller 4 is 180mm.

[0082] The tensile test results of Examples 1 to 8 are shown in the table below:

[0083] Table 1 Tensile test results of AZ31B magnesium alloy ingot 1 after homogenization treatment

[0084]

[0085]

[0086] Table 2 Tensile test results of AZ31B magnesium alloy ingot 1 after extrusion deformation

[0087]

[0088] Table 3 Tensile test results of rolled AZ31B magnesium alloy sheet

[0089]

[0090]

[0091] In the description of this invention, it should be understood that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0092] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method of working AZ31B magnesium alloy sheet material, characterised in that: The method is realized by the following steps: Step S1: firstly, the AZ31B magnesium alloy ingot (1) is put on a car body and polished; then, the AZ31B magnesium alloy ingot (1) is wrapped with dry MgO powder and put into a heating furnace (2) for homogenization treatment, the temperature of the homogenization treatment is 400-430℃, and the time of the homogenization treatment is 10-15h; after the homogenization treatment, the AZ31B magnesium alloy ingot (1) is cooled with the heating furnace (2); after the cooling, the AZ31B magnesium alloy ingot (1) is taken out and polished again; Step S2: the AZ31B magnesium alloy ingot (1) obtained in step S1 is put into the heating furnace (2) and heated to 320-400℃ and kept for 30min, and the extrusion die (3) is heated to 320-400℃ at the same time; then, the AZ31B magnesium alloy ingot (1) is taken out and put into the extrusion die (3) for the first extrusion, the extrusion angle is 90°, the extrusion speed is 0.2-0.4m / s, and the extrusion ratio is 4:1; after the extrusion, the AZ31B magnesium alloy ingot (1) is taken out and immediately water quenched; Step S3: the AZ31B magnesium alloy ingot (1) obtained in step S2 is put into the heating furnace (2) and heated to 250-350℃ and kept for 30min, and the extrusion die (3) is heated to 250-350℃ at the same time; then, the AZ31B magnesium alloy ingot (1) is taken out and put into the extrusion die (3) for the second large deformation extrusion, the extrusion angle is 30°, the extrusion speed is 0.2-0.4m / s, and the extrusion ratio is 25:1; after the extrusion, the AZ31B magnesium alloy ingot (1) is taken out and naturally cooled; Step S4: the AZ31B magnesium alloy ingot (1) obtained in step S3 is put into the heating furnace (2) and heated to 300-400℃ and kept for 30min, and the rolling roller (4) is heated to 200-300℃ at the same time; then, the AZ31B magnesium alloy ingot (1) is taken out and put into the rolling roller (4) for rolling; after each pass of rolling, the AZ31B magnesium alloy ingot (1) is put into the heating furnace (2) and heated to 400℃ and kept for 5min, and then the next pass of rolling is carried out, the rolling speed of each pass of rolling is 0.5-1m / s, the reduction of each pass of rolling is 5-10%, the rolling direction of each pass of rolling is consistent, and the rolling operation is repeated until the AZ31B magnesium alloy ingot (1) is rolled into the AZ31B magnesium alloy plate (5) with a thickness of 1.5-2.5mm.

2. The method of claim 1, wherein the AZ31B magnesium alloy sheet is a 1.5 mm thick sheet. The heating furnace (2) is a resistance furnace; the diameter of the rolling roller (4) is 180mm.

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